Add stubs for icu

This way we don't need to use casts in-code.

3 files changed, 32 insertions, 8 deletions

diff --git a/mypy_stubs/icu.pyi b/mypy_stubs/icu.pyi
new file mode 100644
index 0000000..be46c19
--- /dev/null
+++ b/mypy_stubs/icu.pyi
@@ -0,0 +1,25 @@
+from __future__ import annotations
+
+from typing import overload
+@overload
+def Locale() -> str: ...
+@overload
+def Locale(x: str) -> str: ...
+
+class UCollAttribute:
+    NUMERIC_COLLATION: int
+
+class UCollAttributeValue:
+    ON: int
+
+class DecimalFormatSymbols:
+    kGroupingSeparatorSymbol: int
+    kDecimalSeparatorSymbol: int
+    def __init__(self, locale: str) -> None: ...
+    def getSymbol(self, symbol: int) -> str: ...
+
+class Collator:
+    @classmethod
+    def createInstance(cls, locale: str) -> Collator: ...
+    def getSortKey(self, source: str) -> bytes: ...
+    def setAttribute(self, attr: int, value: int) -> None: ...
diff --git a/natsort/compat/locale.py b/natsort/compat/locale.py
index 53080c3..8d7ae48 100644
--- a/natsort/compat/locale.py
+++ b/natsort/compat/locale.py
@@ -40,19 +40,20 @@ try:  # noqa: C901
     def get_icu_locale() -> str:
         language_code, encoding = getlocale()
         if language_code is None or encoding is None:  # pragma: no cover
-            return cast(str, icu.Locale())
-        return cast(str, icu.Locale(f"{language_code}.{encoding}"))
+            return icu.Locale()
+        return icu.Locale(f"{language_code}.{encoding}")
 
     def get_strxfrm() -> TrxfmFunc:
-        return cast(TrxfmFunc, icu.Collator.createInstance(get_icu_locale()).getSortKey)
+        return icu.Collator.createInstance(get_icu_locale()).getSortKey
 
     def get_thousands_sep() -> str:
         sep = icu.DecimalFormatSymbols.kGroupingSeparatorSymbol
-        return cast(str, icu.DecimalFormatSymbols(get_icu_locale()).getSymbol(sep))
+        return icu.DecimalFormatSymbols(get_icu_locale()).getSymbol(sep)
 
     def get_decimal_point() -> str:
         sep = icu.DecimalFormatSymbols.kDecimalSeparatorSymbol
-        return cast(str, icu.DecimalFormatSymbols(get_icu_locale()).getSymbol(sep))
+        return icu.DecimalFormatSymbols(get_icu_locale()).getSymbol(sep)
+
 
 except ImportError:
     import locale
diff --git a/setup.cfg b/setup.cfg
index 6fd9d1d..a99791c 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -64,6 +64,4 @@ exclude =
 	.venv
 
 [mypy]
-
-[mypy-icu]
-ignore_missing_imports = True
+mypy_path = mypy_stubs